Why do some jail cell bars have a ridge on two sides?

self

[Java4Jay]

I was watching an old movie 'Come and Get Me' with Lloyd Bridges and noticed the jail cell had bars with two ridges. I recalled from my youth seeing the same type bars and had wondered why the ridges. I searched the net with no answer to my question. See picture attached, feedback welcome, thanks.

[Java4Jay]

[llevrok]

Ping for later

[granite]

Perhaps these bars were moulded, not extruded.

[Vermont Lt]

My guess is that there is a solid rod down the middle.

Makes it more difficult to saw through or bend.

[reintarnation]

Not speaking from personal experience, but maybe so they can’t be rotated and worked loose...?

[headstamp 2]

Guesses are, to stop them spinning or maybe they are CAST steel or iron and that is the mold ridge.

[Java4Jay]

The only thing I can think of is to prohibit the bar from being rotated causing wear.

[rstrahan]

Bars are two-piece. The outer bar is rigid, the inner bar is solid, but not fixed so that if someone tries to saw through it, it just rotates, stopping that. The ridges may be the result of the manufacturing process of that era.

[Java4Jay]

Am sure the bars are extruded

[UnwashedPeasant]

"I recalled from my youth seeing the same type bars"

You must have been a tough kid.

[lee martell]

I DARE Alex Trebek to ask such an obscure question on Jeopardy! You’d have the Big Winners giving each other blank stares and goofy grins. They only get what? five seconds to guess before the beeper sounds.

[Bob434]

lol

[dakine]

Reflective movie.. Howard Tyler/Frank Lovejoy could have been me (except, I’m better looking)...

[Bob434]

[[Why do some jail cell bars have a ridge on two sides?]]

Because 3 ridges would be overkill?

[Java4Jay]

Correction: Movie was ‘Try and Get Me’

[Rocko Jack]

That sounds like a winner

[Eagles6]

Asking for a friend?

[SecondAmendment]

You can see that the horizontal crossbar has a notch cut out in it that the ridge has to key into. My guess is that the tolerance of the notch is very tight and is used to make the door more rigid, since there does not appear to be any welds used around the bars.

[Java4Jay]

[dakine]

Gives me chills..